Valve seat grinder



June 29, 1937. M D, TYLER 2,085,280

' VALVE SEAT mammaA Filed Nov. 1, 19254 5y MM' "W 7%@ described in whichthe grinding member may beY .quickly renewed.

Patented June 29, 1937 UNITED s'rAT1a1sl PATENT OFFICEv aoazso- VALVESEAT GRINDER Merle D. Tyler, Chicago, Ill. Application November 1, 1934,Serial No. 750,963

-3 Claims.' (Cl. 5.1-185) 'I'he present invention relates to valve seatgrinders and is particularly concerned with grinders of the type adaptedto be used in grinding extremely hard valve seats of internal combustionengines, such as. for example, the high speed tungsten or stellite steelvalve seat inserts now being used.

One of the objects of the invention is the provision of an improvedvalve seat grinding tool which may be manufactured at a very low costand which is adapted to be utilized in grinding very hard valve seats. A

Another object of the invention is the provision of an improved grinderwhich is simple in construction and requires a minimum amount of machinework in its manufacture.

Another object of the invention is the provision of an improved valveseat grinder which is sturdy and serviceable, accurate, and which may bemanufactured at such a low cost that it may ,be purchased by a vastnumber of users who otherwise could not aord to purchase tools of thistype. v

Another object of the invention is the provision of an improved valve'grinder of the class described which is adapted to-bev used inrelatively inaccessible places, such as on the valve seat located underan overhanging dash.

Another object of the invention ls the provision of an improved valveseat grinder of the class Another object of the invention is the provision of an improved valveseat grinder of the will be apparent from thefollowing description and from the accompanying drawing, in whichsimilar characters of reference indicate similar parts throughout theseveral views.

Referring to the single sheet of drawings accompanying thisspecification, Fig. l is a side elevational view of a valve seat grinderconstructed accordinglto the present invention. shown in connection withan internal sizes.

combustion engine block, the block being in section;

Fig. 2 is a top plan view of thevalve seat grinder;

Fig. 3 is a sectional view taken on the plane of the line 3 3 of Fig. 2,looking in the direction of the arrows, with parts of the, driving shaftin section and other parts in elevation;

Fig. 4 is a bottom plan view of the valve seat grinder, with the pilotin section, on the plane of the line 4 4 lof Fig. 3, looking in thedirection of the arrows;

Fig. l5 is an exploded view ofthe parts of the grinder, showing afragment of the pilot and a fragment of the drive shaft;

Fig. 6 is a plan view of the abrasive covering sheet.

Referring to the drawing, I0 indicates in its ventirety the completegrinding equipment, which preferably consists of a motor such as a drillmotor II having a chuck I2, a drive shaft I3, the grinder I4, and apilot I5.

The equipment is shown in connection with an internal combustion engineblock I6, which is provided with a relatively hard valve seat insert I1,and the usual valve stem guidel8. A number of different pilots I5 areprovided, the sizes being suitable so that the pilots, which areaccurately finished to cylindrical shape, may be rotatably mounted inthe valve stem guides I8 of various types of engines which have guidesof different The valve stem pilots I5 fit the guides I8 closely enoughto center accurately the grinder I4 with respect to the seat I I andwith respect to theaxs of the valve stem guide I8.

Allvof the. pilots are preferably provided with a reduced threadedportion I9 of the same size and preferably having right hand threads sothat the tendency is for the pilot I5 to be threaded home into the bodyof the grinder I4 when the shaft is rotated in a right hand direction.

An annular shoulder 20 is located between the reduced threaded portionI9 and the cylindrical body of the pilot I5, and is adapted to engage aclamping member or spider 2|, which is utilized for securing theflexible abrasive element' 22 on the body 23 of grinder I4.

The drive shaft 3 is preferably, but not necessarily, provided with aflexibleshaft portion 24 located between two shaft sections 25 and 26 sothat the grinder may be used in relatively inaccessible places bydisposing the drive shaft of the motor I I at an angle, as shown in Fig.l, under the over-hanging dash 21. I

The flexible shaft portion 20 may consist of close 'together' andsecured to the reduced ends 28, 23 lof the'shafts 25, 26 respectively.;This coil spring may be secured to the reduced ends 28, 29.111 anyof anumber-of different wayssuch as, for example, by providing the reducedportions 28, 29 with relatively rough threaded formations of such shapethat the coil spring-24 may be threaded over the spring, being threadedAhome against'the annular shoulders 30, 3l.

The size of the cylindrical `parts of the shafts 25'and 26 and the sizeof the reducedportions 28 and 29 lare such that when the spring 24 ispilot I5 below.

located on the reduced portions 28, 29 thel outer surface of thespringis flush with the cylindrical surfaces of the shafts 25, 26. Thesprings may also be secured in place in some embodiments of theinvention by making the reduced portions 28, 29 slightlylarger than thespace inside the spring 24 and forcing the springs on the reducedcylindrical portions 28, 29 where they are 'securedby' the frictionalgrip of the springs against the ends of the shafts. For this purpose thereduced portions 28, 29 may be slightly tapered, if desired.

Springs secured in either of the modes just described may be furtherpermanently secured by welding, soldering, or otherwise. forming arelatively integral bond between the parts of the flexible shaft 24V andthe shafts 25, 26. The lower end of drive shaft 26 is also provided witha reduced threaded portion 32 and with an annular shoulder 33 for use inseeming the shaft to the body 23 of the grinder I4.

The threaded portions I9 and 3 2 are prefer` ably of the same size sothat the aperture or bore 34 in the grinder body 23 may be of the samesize throughout and provided with threads of the same characteristicsfor fitting both the end of the shaft 26 and the end of the pilot I5.Thus thebody 23 may be threaded at one time for attachment ofthe shaft26 above and the The grinder body 23 is preferably formed of die castmetal in a casting operation, and is provided with a plurality offrusta-conical surfaces 35, 36, 31, 38, separated by slots 439. -Thesesections of frusto-conical surfaces 3538 all form parts of the samefrusta-conical surface and correspond in angularity to the angularity ofthe valve seat upon which the grinder is to be used, such as, forexample, forty-five degree valve seats, sixty degree valve seats, orthirty degree valve seats. Obviously, grinders of any angularity may bemade, and those just listed are merely exemplary of the most commonshapes. l

At its lower end the grinder body 23 is provided with a iiatsurface 80,which is adapted to engage the inner fiat side of the clamping member orspider 2l At its upper end the valve seat body 23 is preferably providedwith aflat upper surface 4I which may be engaged -by tool holders insome types of driving equipment, 81nd on other occasions it may beengaged by the driving end of an ordinary valve seat lapping ma'- chine.di is provided with the pairs of holes 42, d3 which perform the'samefunction as the slot or holes in the upper end of the valve stem forreceiving the projecting ends of the plate onv the end of a geared valveseat grinder of the type which rotates-the valve or grinder forward andbackward.

Body 23 of the grinder is preferably longer or deeper in a verticaldirection than the dimen- For this purpose the upper fiat surface r2,085,280 a fairly heavy helical spring havingits-coils sionnecessitated for the frusta-conical surfaces a cylindrical outer surface44. Since a considerable portion of the body is removed in forming theslots 39, it is also desirable to providethe lbody 23 with a cylindricalboss 45 at its upper end, thereby giving the body greater strength andproviding more material for joining the frust-conical parts 35-'38together.

The 'clamping member or spider 2l preferably consists of a spring steelmember which may be made of non-corrodible material, such as stainlesssteel, Aorirom ordinary spring steel. It is preferably provided with acentrally located aperture 46 for passing the reduced threaded end I9 ofthe pilot I 5, and with an annular body 41.

Projecting radially `from the annular body 41 are a plurality ofintegral-strips or spring fingers 88 which have been bent upward fromthe annular body 41 at the points 49 in such manner as to engage theflexible ab'rasive covering 50 and draw it taut on the Afrusto-conicalsurfaces As observed in Fig. 3, the angularity ofthe spring fingers 48is such that any excess of exiicient firmness so that there isnopossibility of its becoming -loose under operation. However, theproportions of `theannular abrasive covering 50 and the grinder body 23are such that the abrasive becomes tight slightly before the clampingmember 2| meets the Vlower end 40 ofthe body 23, and the spring ngers 48are slightlyv iiexed and placed under tension when the clamping member2i is driven home'against the end 48 by the annular shoulder 20 ofpilotl I5.

The abrasive covering I5 may consist of any form of flexible abrasivehaving a paper or fabric base, the latter being preferred on account ofits greater flexibility and greater tensile strength. Therefore, theabrasive covering 58 preferably consists of .emery orcarborundumv35i-38, and is therefore generally provided with 25. yible abrasiveover that required to cover the v cloth in the form of an annulus, asshown in Fig. 6..

It should be observed that the aperture 5I in the annulus 50 is largerinthe blank pattern than it appears in plan, when the slack has beentaken up, and the abrasive is secured to the body 23 as shown in bottomplan in Fig. 4.

It will thus be observed. that I have inventedA be provided with aexible upper shaft at a minij mum expense. by means of the structuredescribed, and the machining operations involved are reduced to aminimum, since the body of the grinder may be cast, and it is onlynecessary to thread the aperture in the body.

While I have illustrated and described a preferred embodiment of myinvention, many modiflcations may be made-without departing from thespirit ofthe invention, and I do not wish to be limited to the precisedetails described, but desire to avail myself of all changes within thescope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In a tool for grinding valve seats, the combination of a supportingbody having a substantially frusto-conical backing surface, said bodybeing formed with a plurality of radially and inwardly extending slots,each of said slots extending substantially in the direction of anelement of said frusto-conical surface located at said slot, a flatannulus of flexible abrasive material carried by said body in engagementwith said l5 backing surface, said annulus having its slack taken up byextending into said slots, and a relatively stii yet resilient metalmember centered on said body outside said annulus and having a pluralityof legs, each of said legs extending 20 into one of said slots, andforcing said slack 'abrasive into said slots, said legs holding saidannulus taut against said frusto-conical surface by virtue of theresiliency of said legs, which are adapted to be flexed to maintain apredetermined 2 5 tension on said abrasive, said body having a threadedbore, a pilot member having a reduced threaded section adapted to bethreaded home in said bore, said metal member having an aperturereceiving said reduced threaded section, and

30 said pilot having a shoulder engaging said metal member to clampsaidmetal member against said body when said legs are placed undertension.

2. In a tool for grinding valve seats, the com- 35 bination of a metalbody provided with a plurality of substantially frusto-conical surfacesformed with the same generatrix and spaced from each other by aplurality of radially inwardly extending slots, said body having a sub-40 stantially iiat upper surfacey and being provided with a centrallylocated threaded bore on its frusto-conical side, a flexible abrasiveannulus of suflicient size so that when it is placed upon thefrusto-conical surfaces of said body and sub- 45 stantially conformedthereto said frusto-conical surfaces will be substantially covered andthe slack of said annulus extends into the slots, the depth of saidslots being sumcient with respect to the amount of slack in said annulusso that '50 the base ofthe slots will notl prevent the abrasive 55 onearm extending into each of said slots, and

said arms extending diagonally from the body of said spider insubstantially the direction of the base of said slots, said arms beingbent at an angle whereby they are adapted to engage the abrasive annulusand take up all of the slack therein and draw the annulus taut on thefrustoconical body when the spider is driven into said slots, and apilot having a threaded end and a shoulder for engaging said spider,said threaded end being located in said threaded bore whereby sad pilotis adapted to exert the tensioning force by driving said spider in anaxial direction toward said body.

3. In a tool for grinding valve seats. the conibination of a metal bodyprovided with a plurality of substantially frusto-conical surfacesformed with the same generatrix and spaced from each other by aplurality of radially inwardly extending, slots, said body having asubstantially flat upper surface and being provided with a centrallylocated threaded bore on its frusto-conical side, a flexible abrasiveannulus of sutlicient size so that when it is placed upon thefrusta-conical surfaces of said body and substantially conformed theretosaid frusto-conical surfaces will be substantially covered and the slackof said annulus extend into the slots, the depth of said slots beingsucient with respect to the amount of slack in said annulus so that thebase of the slots will not prevent the abrasive from being drawn taut onsaid frusto-conical body, a metal spider having a centrally locatedaperture for registry with said threaded bore, and having a plurality ofradially extending arms, one arm extending into each of saidV slots, andsaid arms extending diagonally from the body of` said spider insubstantially the direction of, the base of said slots, said arms beingbent at an angle whereby they are adapted to engage the abrasive annulusand take up all of the slack therein and draw the annulus taut on thefrusto-conical body when the spider is driven into said slots, and apilot having a threaded end and a shoulder for engaging said' spider,said threaded end being located in said threaded bore whereby said pilotis adapted to exert the tensioning force by driving said spider in anaxial direction toward said body, said threaded bore extending throughsaid body, anda drive shaft comprising a threaded metal rod driven homein the upper end of said bore, said rod having a spirally wound exiblesection secured thereto and a second drive rod for grip by a chuckcarried by the other end of said spiral iiexible section.

MERLE D. TYLER.

